Tags designed to identify products, for example bearing a barcode, allow a type of product to be identified, but do not allow it to be authenticated, i.e. verify that it is not a copy, in particular because these tags are easy to duplicate.
One knows the authentication methods and devices described in documents WO 2004/081649, US 2007/091376 and EP 1 986 162. Substantial data throughput and computing resources are utilized in each of these methods and devices. In addition, these methods and devices do not allow visual authentication by the user. On the contrary, authentication is performed automatically. It is therefore subject to algorithm errors or to adaptation, by a counterfeiter, to the algorithms utilized.